But the producers of Poldark have disclosed that the famous scene in which Turner toiled in a field while stripped to the waist was almost dropped because the actor's muscles were deemed too big for the role.

The programme-makers who cast Turner were unaware that he was quite so buff - or that that he had been working out in the gym after landing the part of Ross Turner - and worried that his honed physique did not fit with an 18th century Cornishman just returned from fighting in the US Civil War.

Damien Timmer, executive producer of the BBC One drama, told an audience of Poldark fans at the Radio Times Festival: "We hadn't seen him with his shirt off before we cast him. It wasn't a big thing whether he was going to be shirtless.

"Then we looked at the rushes [uncut footage] and said, 'Blimey, he's so muscly.' [We] worried he was too muscly. There were discussions about whether he just looked too well-built for that moment."

Fortunately for all involved, the scene was left in. And in an interview ahead of the second series, currently filming on the Cornish coast, Turner joked that he might reprise it.

Asked if there would be "any more warm weather scything" in series two, Turner laughed: "Possibly. It depends. It depends if we need the ratings. Oh dear, what has my life become..."

The Irish actor has admitted to spending six weeks in the gym, following a strict diet, in preparation for the role. He also disclosed that a make-up artist daubed him in baby oil for the scything scene in order to give him a glistening torso.

Another of Turner's semi-naked scenes, in which he bathes in a turquoise sea, did not come out as intended.

Debbie Horsfield, the screenwriter who adapted Winston Graham's novels for the screen, said an unusually balmy Cornish summer had altered what should have been a key dramatic moment.

"Anyone who has ever lived in Cornwall or been on holiday in Cornwall knows you can get four seasons in a day," she said.

"But it was the best summer in years. There were times we needed the sea to be really rough and it looked like the Greek islands. The scene where Ross goes into the water - as scripted, it was an angry moment when he dives into these grey, churning waves, and of course he was having to just splash water on himself."

Horsfield said she had been "completely taken by surprise" when Poldark became such an enormous hit and the weight of expectation for series two is "higher than anything I've ever known".

Cast and crew were joined at the festival by the late Winston Graham's son, Andrew, who said his father would have been "absolutely delighted" by the show's success. The books were first adapted by the BBC in the 1970s.